Dressing mechanism



Jan. 9, 1940. A. H. CANDEE ET AL DRESS ING MECHANISM Filed July 24, 1939 2 Sheets-Sheet 1 3nventors gZZazz QziCazzdee 3 (Ittorneg 1940. A. H. CANDEE AL 2,136,363

DRESSING MECHANISM Filed July 24, 1959 2 Sheets-Sheet 2 Zmventors i attorneg Patented Jan. 9, 1940 DRESSING MECHANISM Allan H. Candee and George 0. Richmond, Rochester, N. Y., assignors to Gleason Works, Rochester, N. Y., a corporation of New York Application July 24, 1939, Serial No. 286,080

9 Claims.

The present invention relates to mechanism for dressing grinding wheels.

A primary purpose-of the invention is to provide a dressing mechanism that can readily be adapted to dress a grinding wheel to any desired profile shape.

A further object of the invention is to provide an attachment for a known type of dressing mechanism which will allow that dressing mech- 10 anism to be used to dress an infinite variety of profile shapes by making a simple adjustment and which will obviate the present necessity of employing different formers or guides for every change in profile curvature to be dressed.

Other objects of the invention will be apparent hereinafter from the specification and from the recital of the appended claims.

The invention has various applications. In thedrawings, however, we have shown it applied to the dressing mechanism of a Jones & Lamson thread grinding machine.

The dressing mechanism of such a machine is accurate, precise and entirely satisfactory within its range' The profile shapes which can be dressed with this mechanism, however, as heretofore built, are determined by the formers or guide plates employed in the mechanism. For dressing straight profile shapes, straight-sided guides are used. For dressing curved profile shapes, curved :0 guides are employed, but separate guide plates are required for each shape to be dressed. Moreover, if a guide plate having a guide surface of a particular curvature does not prove in practice to be satisfactory for a particular job, it is necessary to regrind the plate to a diiferent curvature or to make a new plate. We have devised a simple and inexpensive attachment for adapting this dressing mechanism to the dressing of grinding wheels of a wide variety of profile curvatures 40 while using a standard straight-sided guide memher.

In the Jones & Lamson dressing mechanism,

a pair of diamonds are provided for dressing opposite sides of a. disc-type grinding wheel. Each diamond is mounted in a reciprocable plunger for movement laterally of the wheel axis. The two plungers are operated by rocker arms and both the plungers and the rocker arms are mounted in a drum that is movable rectilinearly 59 in a/direction radial of the wheel axis. Each rocker arm. carries a roller that engages a guide plate that has a straight guide surface inclined to the path of movementof the drum. The guide plates are movable relative to the drum. and the 55 guide surfaces of the two plates are inclined to one another in accordance with the included angle between the active side surface of the grinding wheel which is to be dressed. -When the drum is actuated, it moves the diamonds in the general direction of the height of l the wheel profiles and as the drum moves, the rollers carried by the rocker arms roll along the guide plates, rocking the rocker arms to move the diamonds laterally in a plane perpendicular to the central plane of the grinding wheel. The W amount of lateral movement of each diamond is exactly proportional to the rectilinear displacement of the guide plates. Hence, the movement of each diamond isalong an oblique straight line and diamonds, therefore, will dress straight line II surfaces on the grinding wheel inclined to the plane of rotation of the wheel.

The present invention permits the dressing mechanism described to be used with but slight modification thereof to dress any curved profile 20 shape desired. To this end, we retain the straight guide plates of the described mechanism but provide means, such as an eccentric or cam, for moving these plates at a variable velocity. In this way, the amount of lateral movement of the dia- 25 monds is varied and hence is no longer in proportion to the rectilinear movement of the drum. The diamonds therefore no longer dress straight profile shapes on the grinding wheel but curved profile .shapes, the amount of whose curvature 30 depends upon the variation in rate of movement of the guides. The eccentric, which controls the movement of the guides, is preferably constructed so that the amount of its eccentricity or throw is adjustable. Hence, by adjusting the eccentric, 35 varying amounts of curvature may be dressed on the wheel. Moreover, rotary cams can be substituted for the eccentric and a still wider range of profile shapes obtained.

In the preferred construction, a single eccen- 49 tric or cam is employed to control the lateral movements of the two diamonds and preferably 'this eccentric or cam is driven through gearing actuated by the relative motions between the parts of the mechanism itself.- 45

In the drawings: w

Fig. 1 is a more or less diagrammatic perspective view showing the application of a preferred embodiment of the present invention to a dressing mechanism of the Jones & Lamson type and 50 illustrating the mode of operation of the modified dressing mechanism in thedressing of a grinding wheel; j

Fig. 2 is a vertical sectional view through the drum that carries the dressing mechanism;

Fig. 3 is a fragmentary plan view of the drum with parts broken away;

Fig. 4 is a transverse sectional through the forward at the end of the drum and showing particularly the dressing diamonds;

Fig. 5 is a transverse sectional view through the drum taken at a. point to show the operative relation between the guide plates and the rocker arms;

Fig. 6 is a fragmentary view on an enlarged scale showing, in plan, means for actuating the same; and

Fig. "I is a diagrammatic view further illustrating the movement of a dressing diamond in the dressing of a grinding wheel with the mechanism of the present invention.

Reference will now be had to the drawings for a more detailed description of the invention.-

view taken l8 denotes the drum that contains the dressing mechanism. This drum is suitably mounted in the grinding machine for reciprocatory movement. 1

The reciprocatory movement of the drum I is produced by a cam l2 (Figs. 2 and 3) which is keyed to a shaft l3 that is suitably journaled in the drum. The shaft I3 is driven from a motor l4 which is mounted in the drum. The motor drives a. shaft through a suitable coupling 15. This shaft I5 is suitably journaled in the drum and has afworm |1 fastened to it. (Figs. 2 and 5.) The worm |1 meshes with a worm wheel l8 that is secured to a vertical shaft l8 which, is also suitably journaled in the drum. Secured to the shaft I8 at its upper end is a worm 2|! that meshes with a worm wheel 2| which is fastened to the shaft shaft l3 which carries the worm wheel 2| is of reduced diameter as clearly shown inv Fig. 2.

A roller or follower engages in the track 28 of the cam |2.. This follower is carried by a pin 21 which is secured in a bar 28. The bar 281s mounted to slide in suitable bearings formed in the drum Ill. The rear end of the bar engages a roller 30 which is carried by the free end of a lever 3|. drum. Motion of the lever 8| is transmitted to a second lever by a plate 35. The plate 85 has rounded ends and engages in recesses 31 and 38, respectively, in the levers 8| and 35. It is held in operative engagement with the two levers 8| and 35 by a coil spring 44 which is connected at opposite ends to the two levers. The lever 35 is pivoted intermediate its ends, as indicated at 38, in a cover plate 48'that is secured "by. screws 4| to one end of the drum Ill. The lower end of the lever 85 carries a roller 42 which engages witha stud 43 that is-secured in a relatively fixed part 'of the machine; Since the stud 43 is relatively fixed, rotation ofthe cam 12 will be translated through the bar 28 and the reducing levers 3| and 35 into a rectilinear movement of the drum ID in its mounting in the machine. mechanism described, it will be seen that as the cam l2 rotates, the drum |8 will be moved lengitudinally. The design of levers 3| and 35 and of plate 38 is such that the movement of the drum to the frame of the machine is exwith respect actly proportional to the movement of the bar 28 with respect to the drum, but at a slower rate.

The bar 28 slides not only through the bear ings provided for it in the drum l8 but also through an opening in a block 45 which is mounted on the bar. Secured to the block 45 at opposite sides of the the eccentric and the i3. The portion of the' This lever is pivoted at 32 ,in the Thus, through the bar 28, as by means of screws.

41, are two guide plates 45 and 48', respectively, (Figs. 1 and 6). The guide-plates have straight guide surfaces 48 and 48, respectively, that are inclined to the direction of movement 28 and drum ill. The angle of inclination of the guide surfaces 48 and 48 to the direction of movement of the drum is determined by the inclination of the active side surfaces of one grinding wheel, which is to be dressed, to the central plane of the wheel, that is, its plane of rotation. The guide surfaces 48 and 48' engage spherical of the bar rollers 50 and 58', respectively. These rollers are secured in arms 52 and 52, respectively. The arms 52 and 52 are secured to rock-shafts 54 and 54, respectively, that are suitably journalecl in the drum l8.

Fastened to the front ends of the rock-shafts 54 and 54' are arms 55 and 55', respectively, (Figs. 1 and 4). The arms 55 and 55 carry at their upper ends pins 51 and 51', respectively, which engage plane side surfaces of lugs 58 and 58, respectively. These lugs are secured to or integral with plungers 50 and 60', respectively. The plungers are mounted in alignment in suitable'bearings in the drum III to slide toward and from one another. They are normally springpressed toward one another by coil springs 52 and 52 which are mounted in; recesses in the plungers and which engage at one end with plates 53 and 53', respectively, that are secured in the drum. At their adjacent ends, the plungers carry the dressing diamonds'D and D; for dressing optheforegoing description that when means 15 wheel W employed described is of known as'is employed in the provided for moving. the guide plates 45 and 45" 50 and 50' will roll with the bar'28, the rollers on the guide plates. left, then, 2, the arms 55 and 55' will be rocked to move the diamonds D and D apart at the, same time that they are movediinwardly from the periphery toward the'axis of the. wheel by the movement of the drum itself.

As the drum moves to the Secured to the bar" at opposite sides of the block?v are blocks 55 and 55. may be fastened to the bar by'the pin 21. plates 55 and 55 are .spaced apart a. /distance somewhat greater than the width of the block 45 to permit some travel of the bar 28 relative to the block 45.

There is a stud 58 secured lathe/block 45. R0- tatably mounted on this stud is a spur gear 10. Integral with the gear is an eccentric collar 1|. A ring 12', that is provided with an eccentric bore is fitted on this. collar 1| and is rotatably adjustable thereon. 1 Ring andcollar may be suitably graduated to permit this adjustment to be made precisely.

Secured in the v is mounted the roller 15. This roller is adapted to engage the periphery of the ring 12 when the drum l8 moves to the left from the position shown in Figs. 1 and 2.

The gear 10 meshes with a rack which is secured by set screws 8| to a, bracket 82 (Fig. 6). This bracket is fastenedin any suitable manner to the interior of the drum. A gib or clip 83 that is secured to or integral with the block 45 assists, also, in holding the rack in position.

The eccentric 12 operates, during movement of the drum M, to cause a relative displacement to It will be seen. from from the'p'osition shown in Figs. 1 and The blocks 55 The 50 block -86 is a stud 1.5 on which of the guide-member relative member to the dressing tool to move the dressing tool on movement of the guide member, and means for moving the guide member at a varying velocity during movement of the carrier.

5. In a dressing mechanism, a carrier movable in the general direction of the height of the surface to be dressed, a guide-member movably mounted" on the carrier and having a straight guidesurface inclined to the path of movement of the carrier, a dressing tool mounted in the carrier means operatively connecting the guide member to the dressing tool to move the dressing moi laterally in aplane perpendicular to the plane of movement of the carrier on movement to the carrier, means for moving the carrier, and means actuated by the movement of the carrier for producing relative movement between the guide-member and the carrier at a varying velocity.

6. In a dressing mechanism, a carrier movable in the general direction of the height of the surface to be dressed, a guide member movably mounted on the carrier and having a straight guide surface inclined to the path of movement of the carrier, a dressing tool mounted on the carrier, means operatively connecting the guidemember to the tool to move the tool laterally in a plane perpendicular to the plane of movement of the carrier when the guide-member is moved relative to the carrier, a rotatable cam for moving the guide member relative to the carrier ata varying velocity, means for moving the carrier, and means actuated by the relative movement between the guide member and the carrier for rotating said cam.

'7. In a dressing mechanism, a carrier movable on the frame in the general direction of the height of the surface to be dressed, a guidemember movably mounted in the carrier and having a straight guide surface inclined to the path of movement of the carrier, a dressing tool mounted on the carrier, means operatively connecting the guide-member to the dressing tool to move'the tool laterally in a plane perpendicular to the plane of movement of the carrier when the guide-member is moved relative to the carrier, a rack secured to the carrier, means for moving the carrier, and means for moving the guide-member relative to the carrier comprising a gear which meshes with the rack, and a control member secured to the gear that is constructed to impart movement at a varying velocity to the guide member, when rotated.

8. In a. dressingmcchanism, a pair of dressing tools mounted so as tofldress, respectively, opposite sides of a grinding wheel, means for moving'the tools together in one direction, separate mechanisms for movingeach of the tools in a direction inclined to the first named direction to vary thedistance between the two tools during their first named movement, and a single control means for actuating the two mechanisms at a varying velocity.

9. In mechanism for dressing the side surfaces of a grinding wheel, a carrier movable in the general direction of the height of the surfaces to be dressed, a pair of guide-members movably mounted in the carrier, each of which has a straight guide surface inclined to the direction of movement of the carrier, the guide surfaces of the two guide members being inclined to one another in accordance with the angle between the opposite side surfaces of the wheel to be dressed, a pair of dressing tools mounted in the carrier, means operatively connecting the guide members with the tools to vary the distance between the tools when the guide-members are moved relative to the carrier, means for moving the carrier, and means operative on movement of the guide members relative to the carrier for moving the guide-members relative to the carrier at a varying velocity.

ALLAN H. CANDEE. GEORGE O. RICHMOND. 

